Improvement in piano-forte actions



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PATENT OFFICE.

THADDEUS P. CARR, OF YELLOW SPRINGS, OHIO.

IMPROVEMENT IN PIANO-FORTE ACTIONS.

Specification forming part of Letters Patent No. 179,397, dated July 4, 1876; application filed April 17, 1676. l

To all whom fit 'may concern:

Be it known that I, THADDEUS P. GARR, of Yellow Springs, Greene county, Ohio, have invented a new and useful Piano Action, of which the following is a specification:

My invention relates to that class ot devices commonly known as repeating pi ano-actions 5 and my improvement comprises a novel application of the back catch or stop, that arrests the hammer after the latter has recoiled from the wire.

Heretoi'ore these catches have been either rigidly attached to the key, or else constructed in such amanner as not to sustain the entire weight of the hammer until the jack re-engages with the knuckle, which arrangement renders the action either non-repeating, or too complicated for practical use. Ientirely overcome these objections by securing the back-catch to a bearing that is pivoted to the key, said bearing being operated on by the toe of the jack, so as to cause the back-catch to follow the hammer very closely, and arrest the latter with the utmost promptness at any desired distance, after it has recoiled from the wire, and sustaining it in such position until the jack has re-engaged with the knuckle, as hereinafter more fully described.

' In the annexed drawings, Figure 1 is a vertical section through a piano-action embodying my improvements, the various operative parts being shown in their normal positions. Fig. 2 is a similar section, but showing the position the various parts assume immediately upon the recoil of the hammer from the wire, said hammer being represented as supported by the back-catch. Figs. 3 and 4 are diagrams representing modifications of the invention.

A represents a portion of the bed-plate or base of a piano-action, which plate is provided withxthc customary bearing B, that has the key C applied to it in the usual manner. The inner end of this key is gained or notched at c, to receive a block, D, that is attached to said key bypcrew E. The rear end of said block is furnished with a pivot, d, that supports the back-catch bearing F, whose inner end is slotted at f,"to allow free passage of the screw-threaded steml, which projects rigidly from the upper side oikey U. rThis stem is furnished with two adjustable and cushioned stops or buttons, h h', for limiting the vertical vibra-tion of said pivoted bearing F. Hinged to this bearing at 'i is a lever, I, whose front end is traversed by the regulatingvscrew J, the latter being tapped into the short arm K ot' s aidbearing F. L is a spring that maintains lever I in contact with the head of screw J. Attached to bearing F, between slot fand pivot t', is a rod, M, that carries the customary cushioned back-catch m. N is the jack-bearing, attached to key C by regulating-screws n n.` The jack 0 is pivoted to this bearing at o, and is provided `with the customary rearwardly projecting toe P. Extending from jack O to bearing N is a spring, Q, which has a constant tendency to draw the free end of said jack under the knuckle R, the latter bein g pivotedat s to butt-blockS.` This buttblock is secured to the hammer-rail T. Projecting rearwardly from knuckle R is a shaft, U, secured to the shank v of hammer V. YV is the regulating-rail, having a vertical aperture, w, in it, and a notch or cove, w', in its front edge. This rail is traversed with the customary screw X, against whose pad, x, the toe P oi' jack O strikes when the rear end of key Gis elevated. t is a notch in the front edge of rail T, to facilitate the adjustment ot' jack-bearin g N n n'. Y is the wire or string, and Z is a cushion for the rear end of key C to rest on when not in use.

The operation of my action is as follows: When the key C is at rest, its rear end is supported upon cushion Z, while the downward movement of the slottedV end of bearing F is limited by the button h. In this position of the key the back-catch m is not in contact with hammershank c neither does the toe P bear against the lever Ior pad cc. When the rear end of key G is elevated, the front end ot' lever I is at once brought in contact with toe P, which latter exerts sufficient pressure upon said lever to cause its rear end to rise gradually as far as the button h will permit. This elevation of the rear end of bearing F compels the back-catch m to follow the hammer very closely, but without coming in actual contact with its shank o. The further elevation of the rear end of key C brings the toe P in contact with stop ac, thereby disengaging jack O from knuckle R, and causing hammer V to strike string Y and recoil therefrom, when the hammer shank e immediately cushions upon backcatch m. This back-catch now supports the entire weight ot the hammer, and will continue to do so until the key is allowed to rise slightly under the pert'orme1"s finger. The moment this happens spring Q draws jack upward, thus reengaging the latter with knuckle R, and enables another blow to be instantly struck. When the performer lstrikes a very hard blow, the hammer recoils from the string Y with such force as to cause the pi voted bearing F to be depressed against button h. The strength of spring, L will now support the hammer in this position until the key rises slightly and allows jack O to again re-engage under knuckle Ri By properly regulating the adjusting de vices h, h', J, and ai, the movements of the various parts may be so timed with reference to each other as to render the catch m effective as soon as the hammer has recoiled far enough to prevent blocking the strings. The 'perforationw enables the adjustment of screw J, while notch w allows the screw E to be regulated.-

As thc back-catch bearing, operated by the toe ot' the jack, is the principal feature ot' my invention, I reserve the right to modify the construction of said bearing to suit circumstances. One'moditication is seen in Fig. 3, where a long late-s[.)ring', L', is substituted for the bent spring shown in Figs. 1 and 2. In Fig. 4, a coiled spring, L, is employed; but in both of these modifications the action is cssentially the same, although the position ot' the pivot with reference to bearing F is changed.

I claim as my invention- 1. The backcatch M m, rigidly secured to pivoted bearing F d of key C, which bearing is operated by toe P ot' jack O, substantially as described. v

2. The combinatiox'l of key C, pivoted bearing F f i d, stein Il h' h', lever I, spring L, jack 0 I Q, and adjusting devices J X a', as and for the object stated.

1n testimony ot' which invention 1 hereunto set my hand.

THADDES P. oai-zn.

Witnesses:

JAMES H. LAYMAN, J. B. UoNKLlN. 

